Many different types of impact tools are known in the art. In U.S. Pat. No. 4,675,968 to Bartlett, a slide hammer-type puller and installer assembly is described. The slide hammer-type puller and installer assembly includes a shaft with an enlarged abutment disposed at one end and an enlarged adapter disposed at the other end. A weighted impact member which is also used as a hand grip is slidably mounted on the shaft between the abutment and the adapter. The weighted impact member slides along the shaft for selective impact with either the abutment or the adapter. Both the abutment and the adapter are threadedly engaged with the shaft.
U.S. Pat. No. 2,934,984 to Woodman discloses a dent removing hand tool for sheet metal. The dent removing hand tool includes a shaft and a weighted, cylindrical sleeve. The shaft has a first stop block at one end, a handle at an opposite end and a second stop block disposed between the first stop block and the handle. The sleeve slides along the shaft between the first and second stop blocks and selectively impacts either one of the stop blocks. A dent puller adapter is threadedly connected to the first stop block for engagement with the sheet metal.
Another hand tool for removing dents from metal is taught in U.S. Pat. No. 2,941,429 to Mason. This hand tool includes a shaft with a pair of stop members disposed apart from one another and a weighted sleeve slidable along the shaft between the stop members. The sleeve also acts as a hand grip. Each of two different puller adapters are connected to the shaft adjacent respective stop members. As previously described, the sleeve slides along the shaft for impacting a selected one of the stop members.
In U.S. Pat. No. 4,235,090 to Wightman et al, a dent pulling tool is disclosed. This dent pulling tool has a shaft with an interchangeable weighted head, a weight/hammer slidable along the shaft and a handle. The shaft has a handle stop member adjacent the handle and a distal stop member. The interchangeable weighted head pivots about an end of the shaft that is disposed opposite the handle. The interchangeable weighted head in an axially aligned position with the shaft is inserted through a hole formed in the dented material and is then pivoted to cause the interchangeable weighted head to move in a crosswise position relative to the shaft to form an anvil against the dented material.
U.S. Pat. No. 3,113,478 to Hall et al and U.S. Pat. No. 4,034,594 to Morgan also tech impact tools with a weighted sleeve slidable along a shaft for impacting a selected one of stop members disposed on the shaft.
However, each of the impact tools noted above has a drawback with regard to user safety. It is possible during use of these impact tools that one of the user's hands could slip off the tool while the sleeve is approaching impact with the selected stop member. If this occurs, a body part of the user such as a finger or portion of his/her hand could be crushed between the impacting sleeve and stop member. Thus, there is a need to provide an impact tool designed in such a manner that it would be impossible for the user to crush a finger or a portion of his/her hand while using the impact tool. The present invention satisfies this need.